1. Field of the Invention
The invention relates to micro-modules intended to be inserted in an electronic reader for an authentication of the holder of such a micro-module or for reading of a number of rights recorded in such a micro-module.
2. Description of Related Art
A micro-module is typically a chip card, in the form of a SIM card, a credit card or a prepaid card.
Such a micro-module can also be a key functioning in accordance with the USB communication protocol, exhibiting a form of a rigid finger or any other shape.
Such micro-modules always conform to a number of form constraints. Thus, in the case of chip cards, as the card interacts with the outside world by means of electric contacts and a standardized protocol, the form factor remains fixed in the “ISO” format or in the “PLUG-IN” format.
The card must be easy to produce and comply with a very precise dimensioning in order to allow the positioning of the electrical contacts at right-angles with the brushes of the connector of the reader.
The thickness of the card itself is standardized in order to ensure a correct functioning in the reader and in order to keep the general ergonomics of the chip card. This thickness of approximately 0.8 mm is a very strong technical constraint.
By way of illustration, we will cite a case where we have attempted to incorporate in a single plastic card body an indicator and a key in order to offer supplementary features and make from this card a small computer with its peripherals. The difficulty encountered with these solutions is the availability of components such as LCD displays, batteries, and display drivers that can be housed in the 0.8 mm of thickness of the card body and that are sufficiently robust to resist production steps and mechanical stresses during the life of the product. The dimensional constraints that apply to the card are particularly limiting in the case of cards equipped with a user interface.
The advent of contactless cards can now provide a first product offer for banking, transport, or access control applications; however, the production steps for contactless cards remain long and costly. And, although radiofrequency communication no longer imposes a precise dimension of the card, the shape and size of the antenna impose a card size that remains equivalent to the ISO size. The dimensional constraints thus remain in force also in the case of contactless communication cards.
In order to be differentiated, card issuers can therefore rely only on the appearance of the card (colour, transparency) and not at all on the shape.